Julie,
I think that's more a matter of taste than absolute fact. While I love the quality of light in the early morning and late afternoon, it is also much more directional at those times making for stronger shadows. If that's what you're after in your portraits, then it's perfect.

I'm more into a flatter overall light both in the studio and in the field which is why I prefer open shade with a small amount of fill-flash. That's just the look and quality of light I prefer.

Neither is right and neither is wrong. I've gotten some lovely late afternoon portraits. But the bulk of my work gets done when it's convenient for the clients and their dogs and that's not always easy to force into the early morning or late afternoon hours. So I've gotten to the point where I prefer to shoot where I know I'll have good, controllable light at virtually any hour of the day.

Having seen your work from Perry, shooting late in the day gives you lovely light without question and you certainly know how to use it.

Jim